The disclosure relates generally to optical signal or communication fibers and more particularly to optical communication or fiber ribbons. Optical fibers have seen increased use in a wide variety of electronics and telecommunications fields. Fiber optic ribbons may hold multiple optical fibers together in a group or array. The fiber optic ribbon includes a body formed from a material that holds the optical fibers together and/or that provides structure that assists in the handling and connecting of the optical fibers of the ribbon to various components or devices.
Optical fibers may include a glass core surrounded by a glass cladding. The cladding, in turn, may be surrounded by polymeric layers. Typically the polymeric layers include a stress-isolation or -absorption layer and then a harder outer shell layer. The polymeric layers tend to be rather thick in proportion to the core and cladding such that the polymeric layers may double the diameter of the optical fibers or more. Accordingly, fiber optic ribbons made with such optical fibers are wide relative to single optical fibers or glass portions thereof. The fiber optic ribbons require a corresponding large amount of matrix material to bind the optical fibers together, and may be cumbersome to connectorize in small form-factor connectors because the optical fibers may need to be removed from the ribbon matrix, stripped of their polymeric coatings, and then re-aligned when inserted in the connectors.
Some fiber optic ribbons may be substantially narrower, such as by removing the polymeric layers of individual fibers and then placing the fibers together in the ribbon. For example, the optical fibers in the ribbon may include glass and only a single polymeric coating, such as a hard shell; instead of the above-described dual-coating system. Some ribbons constructed with such optical fibers place a single, combined stress-isolation layer for the entire fiber optic ribbon around the individual fibers, which may then be surrounded by a hard outer shell for protection of the fiber optic ribbon.
However, removal of the individual polymeric layers of optical fibers, especially the stress-isolation layers, and then close placement of the optical fibers in a fiber optic ribbon may lead to increased attenuation of the optical fibers due to fiber-on-fiber contact and/or fiber-on-fiber loading within the fiber optic ribbon, such as when the ribbon is bending or twisting, especially if the stress isolation layer of the individual optical fibers is not present. Further, in some such fiber optic ribbons, removal of the polymeric coatings may obscure the identity of individual optical fibers in the fiber optic ribbons by making the optical fibers clear within the matrix and/or making the optical fibers indistinguishable from one another.
A need exists for (1) a fiber optic ribbon that is narrow and compact, reducing the volume of matrix material associated with conventional fiber optic ribbons and/or allowing for direct connectorization in small form-factor connectors; (2) narrow and compact fiber optic ribbons to be constructed in a manner that mitigates fiber-on-fiber contact and/or fiber-on-fiber loading within the fiber optic ribbon, such as when the ribbon is bending or twisting, to improve the performance of such fiber optic ribbons in terms of optical fiber attenuation; and/or (3) for differentiation of the individual optical fibers within the fiber optic ribbons, such as while maintaining the narrow geometry and/or attenuation mitigation attributes of the fiber optic ribbons.